


[Commission] To Sleep, Perchance To Diaper

by BabyLily



Category: Miraculous Ladybug
Genre: ABDL, Babysitting, Diapers, Gen
Language: English
Status: Completed
Published: 2017-12-11
Updated: 2017-12-11
Packaged: 2019-02-13 13:09:27
Rating: Mature
Warnings: Underage
Chapters: 1
Words: 3,616
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12984738
Author URL: https://archiveofourown.org/users/BabyLily/pseuds/BabyLily
Summary: Manon has been wetting the bed, but when she sleeps over at Marinette's, she really doesn't want to wear her pull-ups, since she's not a baby. Marinette manages to get the little devil into her proper nightwear, but she'll soon realize how it feels to be treated younger than you really are...





	[Commission] To Sleep, Perchance To Diaper

**Author's Note:**

> A Miraculous Ladybug fanfic, written by me, commissioned by someone who chose to remain anonymous.

“NO!”  
  
“Manon, please!”  
  
“NO NO NO!”  
  
Marinette was panting so hard, she expected her lungs to fall out at any moment. Five minutes ago, she told Manon to get ready for bed. Unfortunately, that also meant that all the nice things about this day – the ice cream, the walk in the park, playing with the Ladybug and Cat Noir dolls and so on – were quickly overshadowed by the dreaded package still resting on Manon's makeshift bed. A package Marinette had almost forgotten about, but when she got out the girl's pajamas, she noticed it, gulped, and reminded her charge to put on what was in it before going to bed.  
  
And then the chase ensued.  
  
“Please, your mom...”  
  
“I DON'T WANT TO!”  
  
“But...”  
  
“I'M NOT A BABY!”  
  
Of course she wasn't. But she did have problems with keeping the bed dry recently, according to her mother, and since she was staying over night today, she would have to wear her pull-ups.  
  
As Marinette chased after the young girl, she lamented her current position. Why tonight, of all nights, did both her parents and Alya have to be out of town?  
  
“I'M NOT WEARING DIAPERS!”  
  
“They're not diapers, they're...”  
  
“LALALALALALA...”  
  
Thankfully, even with all the energy of a tantrum-throwing toddler, Manon was not much of a match for the girl who regularly ran and jumped across the rooftops of Paris to fight super villains. So eventually, Marinette managed to catch the screaming whirlwind.  
  
“Manon, now listen! Your mom told me that you need these, so you're going to wear them! I know you don't like them, but please! It's not like any of your friends will see you! It'll be our secret!”  
  
“But...”  
  
“NO BUTTS EXCEPT YOURS IN THAT PULL-UP!”  
  
Marinette was shocked at herself. She rarely raised her voice, much less against Manon. But something about this situation just seemed to bring out her angry side.  
  
Manon was shocked as well. But her shock (probably combined with the exhaustion from running around and throwing a tantrum) turned into angry silence. Marinette realized that, at least right now, she was the bad guy. But at least, she was the bad guy in charge.  
  
“Now...are you gonna put this on yourself, or do I actually have to put it on you like a baby?”  
  
Manon angrily grabbed the pull-up and walked upstairs without a word. A few seconds later, Marinette walked in to see her lying in bed.  
  
“Lift your blanket.”  
  
Dejectedly, Manon did as she was told, and showed Marinette that she was indeed wearing what she saw as diapers. Marinette smiled and moved her hand to gently pat the little girls cheek.  
  
“There. Now was that really that bad? You...”  
  
Before she could really reach Manon's cheek, her hand was swatted away.  
  
“Easy to say for you.”  
  
“What?”  
  
“Well, you're not the one forced to wear stupid diapers...”  
  
“Manon, they're not...”  
  
“Hmpf.”  
  
With that, Manon turned her back towards Marinette, clearly showing that the conversation was over. Marinette just shook her head and, since the whole day, and especially Manon's tantrums had powered her out, decided to also hit the hay. She quickly changed into her pajamas and let herself fall into her bed.  
  
It didn't take long for her to drift away into the land of dreams.  
  
  
  
A ray of sunshine woke Marinette up. She slowly opened her eyes and got startled as the first thing she saw was her wearing a red outfit with black spots. Did she accidentally transform while asleep? Was that even possible? As she tried to make sense of the situation in her groggy state, she realized she could not be transformed.  
  
Because Tikki was floating above her.  
  
“Tikki! Get down there! What if somebody sees you?”  
  
But Tikki didn't respond. She just started slowly floating in a circle. And behind her...floated another small creature.  
  
“Wha...”  
  
Marinette rubbed her eyes and focused more on what was above her. And she realized that that wasn't really Tikki! It was some sort of figure, looking like Tikki, alongside other small, fantastic looking creatures, dangling from...a mobile!  
  
“What the...”  
  
As she started looking around more, she noticed that she wasn't lying in her bed. She was actually lying in a crib! And the room she was in, while built just like her room, looked much more like a nursery, with pastel colors and childish designs and toys everywhere.   
  
“What is going on?”  
  
She sat up, and then a new realization dawned on her. She quickly looked down and saw that not only was she wearing a red and black onesie, but that onesie also clearly showed some sizable bulk around her waist.  
  
“It can't be...I'm not really wearing...”  
  
She shuffled around on her butt and heard the same crinkling noise she also heard when she first sat up.  
  
“I'm wearing a diaper!”   
  
She couldn't spend much more time on contemplating her current situation as just then her parents entered the room.  
  
“Ah, she's already awake! Hello there, sweetie pie! Are we still dry?”  
  
Before Marinette could even think of responding (or about why her parents acted like everything was normal), her mom had already put a hand to her crotch, lightly pressing the front of the diaper, which crinkled in response.  
  
“Good girl! Doesn't seem soggy at all.”  
  
Marinette couldn't help but blush at the infantile way her mother talked to her.  
  
“M-mom! Of course I'm dry! I don't need...”  
  
“Marinette, not again! I know you think you don't need to wear diapers, but this thing over here says otherwise...”  
  
Her mom walked over to where Marinette remembered her desk being, but where she could now see a big changing table, with a sort of bin next to it, decorated with colorful, childish letters spelling out the words “Baby Mari's Diaper Pail.” As her mother opened the lid and tilted the pail slightly, a pungent smell hit Marinette's nose and she could see that it was at least halfway filled with used diapers. She couldn't help but let her mouth fall open.  
  
After putting the diaper pail back in its place, Mrs Dupain-Cheng went back over to her daughter's crib.  
  
“It's okay, sweetie. I'm sure it will only be a while until we can get you started on proper potty training.”  
  
Marinette blushed again, her cheeks now almost rivaling her sleepwear in terms of redness. She wanted to respond, but before she got a word in, her dad addressed her mom.  
  
“Umm, honey...we're running kinda late...”  
  
Marinette's mom took a look at her watched and gasped with surprise.  
  
“This late already? We really have to get going!”  
  
She turned back to her daughter.  
  
“Don't worry, sweetie. Mommy and daddy will be back home soon. Until then, you can spend some time with your favorite babysitter!”  
  
Marinette was just feeling a mix of confusion and frustration. What was going on? Why were her parents treating her so weird? Where was Tikki? How...wait, did she just say...  
  
“Babysitter?”  
  
“Yes, honey! Aww, I'm so proud that you said it right this time!”  
  
What was she talking about? Why wouldn't she know how to say babysitter?  
  
“But yes, your favorite babysitter!”  
  
She turned around and shouted downstairs.  
  
“You can come up now!”  
  
And then, walking up those stairs to her...nursery, Marinette saw none other than...  
  
“Manon?”  
  
“Yes, sweetie! Right again!”  
  
Her mother sounded proud, but that only made Marinette feel more ashamed.  
  
  
  
Marinette's parents had left, and she was now alone, with who was supposedly her favorite babysitter.  
  
“Hello Mari! Did we have a nice napnap? No accidents?”  
  
What was happening? This pre-schooler who didn't even reach up to her waist was talking to Marinette like she was the little baby here!  
  
“Manon...”  
  
Before she could finish her sentence, Manon interrupted.  
  
“Right! That's my name! You didn't mess it up this time!”  
  
Again, Marinette blushed. Why was everyone complimenting her on getting the most simple of words right?  
  
“Anyway, time for baby's num-nums!”  
  
Manon seemed to unlock something at the side of the crib, which now opened up like a door. The pint-sized babysitter stretched out a hand and without thinking, as if she wasn't fully master over her own actions for a second, Marinette took hold of the hand and started walking – no,  _crawling_  after Manon, who was leading the way downstairs.  
  
Somehow, she didn't seem to register what happened within the next few seconds, but she suddenly found herself sitting in an oversized highchair in the kitchen, with Manon scooping up some mushy food and moving it toward Marinette's mouth.  
  
“Here comes the airplane! Prrrrrttt...”  
  
With a *plop* the spoon landed inside Marinette's mouth. Applesauce. Could be worse.  
  
“Manon! What's happening? I'm not a baby, and you're not my babysitter! I'm your babysitter!”  
  
Manon looked at the diapered girl in front of her in puzzlement. But she quickly seemed to understand what was going on.  
  
“Oh, I get it! We'll see if we can play babysitter later, Marinette. First, you gotta eat the rest of your applesauce, and then you'll have your bottle. We both know how cranky you can get without it, don't we?”  
  
Manon winked and laughed a little.  
  
“What? No! It's not a game, I-...hrmpf!”  
  
One more spoonful of applesauce quickly silenced the the fussy baby.  
  
Just as she wanted to try one more time, she felt her mouth filled again, this time with the nipple of a baby bottle full of warm milk. A nipple she couldn't help but suckle on.  
  
“There, Baby Mari. Drink your milky for Manon. Such a good girl.”  
  
Marinette blushed, but had no choice but to finish the whole bottle.  
  
“There. Now just a quick diaper check!”  
  
The girl in the highchair squirmed in embarrassment as Manon pressed her crotch, just like her mother did before. And what the smaller girl said after that somehow made it even more embarrassing.  
  
“Wow, still dry! Such a good girl. But that's not all, now is it?”  
  
Marinette wondered what she meant, but quickly realized it as Manon seemed to...sniff her butt? No! Her cheeks were blazing red now. Everyone thinking that she'd still wet herself was bad enough, but the implication that she'd also use her diapers to...  
  
“And no poo-poos either! Good!”  
  
“O-of course not! I don't...poop my pants...”  
  
Marinette felt so awkward about having to reassure a girl less than half her own age that she did not soil herself like a two-year old. Manon, in response, just put on a smug look.  
  
“Uh-huh. I think the three dirty diapers I changed you out of last time would disagree. And your parents even said that was a small amount for you.”  
  
Again, Marinette's head looked more like a shocked tomato. She didn't need diapers! And she especially didn't need them to poop! And she  _especially_  especially wouldn't poop herself more than three times a day!  
  
“Anyway, good thing I won't have to change you before we go.”  
  
Manon said, as she made her way back upstairs.  
  
“G-go? Go where?”  
  
Manon came back down with a folded up stroller that she began to unfold.  
  
“It's such a nice day, so we're going to the park!”  
  
  
  
Marinette's heart was racing as they were strolling through the park. She would have run away, were she not strapped into this childish baby stroller. Her outfit made it even worse, since Manon had changed her from her Ladybug onesie into a pastel pink shirt with a big heart on the front. But that wasn't that bad. No, the bad part was that she was wearing absolutely nothing on her lower body. No pants, no skirt, nothing to hide her thick diaper. Looking at the embarrassing garment that was covering her nether regions, made her nervous enough that she was actually suckling on the pacifier Manon put in her mouth “to make her less fussy.”  
  
The diaper seemed so strange to Marinette. It looked like a typical Pampers Baby-Dry that a two year old would wear, but this one was not only big enough to be worn by Marinette, but also visibly thicker.  
  
The big baby was ripped out of her thoughts by the voice of her babysitter.  
  
“Look! Over there!”  
  
Marinette looked, and what she saw made her pacifier fall out of her mouth.  
  
“Hello there, Manon. Babysitting again?”  
  
The red and black clad superheroine smiled first at Manon and then at Marinette in the stroller.  
  
“L-Ladybug...?”  
  
“Yes, Baby Mari! I'm Ladybug!”  
  
“She's been doing so well with her words lately.”  
  
Marinette would have been embarrassed by the compliment from Manon, but she was too flummoxed by her alter ego standing right in front of her. And...giggling.  
  
“Hehe...well, maybe her talking has improved but apparently not her potty training!”  
  
Oh no! Did she...?  
  
Looking down, she did indeed notice her Pampers changing color from a clear white to a faint yellowish tint.  
  
“Uh-oh! Looks like Baby Mari made wetsies!”  
  
Almost crying at her situation and Manon's comment, “Baby Mari” didn't even protest as her babysitter took her out of the stroller and put her down on a nearby bench and took out a fresh diaper and some changing supplies.  
  
“Don't worry, little girl. Your babysitter will change you out of this yucky diaper really quickly.”  
  
Ladybug's words did not really help. Every step of the procedure felt like an agonizing, humiliating eternity.  
  
First, Manon undid the tabs on the diaper and folded it open, mentioning what a heavy wetter Marinette was.  
  
Then she balled up the used diaper and threw it in the nearby waste bin, leaving Marinette's private parts exposed to the eyes of Ladybug and any random stranger that might be passing by.  
  
“Lift your bum, baby.”  
  
Almost automatically, Marinette did as she was told, while Manon put another diaper under her exposed rear.  
  
The cold wetness of the baby wipe made Marinette cringe and the smell of the baby powder made her feel somehow even more childish.  
  
“There,” Manon said, closing up the fresh diaper, “isn't that better?”  
  
It did indeed feel better to finally have this demeaning ritual be finished.  
  
“C-can we go home?”  
  
Marinette hated how her request sounded like something a toddler would say.  
  
“If you want to. Your parents should be home soon any-”  
  
Manon was interrupted by what sounded like a cellphone ringtone. The small girl pulled a phone out of her pocket, looked at the screen and turned to Ladybug.  
  
“Could you watch her for a second?”  
  
The superhero nodded and took Marinette in her arms, while the diapered girl looked after Manon, who was talking to someone on the phone. As she came back, she took Marinette in her arms and strapped her into the stroller while explaining:  
  
“Bad news, Mari. Your parents will be away for longer than they thought, and I have something to do soon. But I know a daycare I can bring you to, where you can stay until your parents come back. But we have to hurry a little. Say bye-bye to Ladybug.”  
  
Still in a state of shock and shame, Marinette just waved at Ladybug, who waved back and then swung up to the nearest rooftop, while Manon drove the stroller out of the park.  
  
  
  
She thought it couldn't get any worse. But now, she was sitting here, on the floor of the daycare center, surrounded by literal babies, playing with some dumb blocks. The worst part was that, besides her height, there was nothing that distinguished her from her “peers”: Her clothes, her pacifier, and of course her thick, crinkly diaper were probably the reason why she wasn't put with the 4 to 6 year old “big kids” when Manon brought her here.  
  
But now, it really couldn't get any worse.  
  
Marinette was just mindlessly playing with some blocks and dolls, always trying to focus on her bladder, as to not wet herself again and make her seem even more fitting into the environment she was in, when she heard one of the daycare workers talk outside the room.  
  
“Ah, you're our teenage volunteer? Thank you so much for wanting to help out. Here, come with me, you'll help take care of the really little ones today.”  
  
Teenage volunteer? Who could that be? Marinette looked at the door, waiting for this new caretaker to enter. What she saw made her drop her pacifier again.  
  
“No!”  
  
Both the older lady and the light-haired young man looked at her as they heard the exclamation.  
  
“Ah, yes. This is Baby Mari. Her babysitter brought her here earlier. She seems to be a really good talker, but still, when it comes to her potty training...”  
  
The boy smiled and chuckled a little, then approached Marinette and kneel down to her.  
  
“Hey there, Mari. I'm Adrien.”  
  
“A-A...Adrien...”  
  
“Yes! Wow, you are a good talker, aren't you?”  
  
She was frozen. She couldn't move. What was happening? Why was it happening? This couldn't be true! She couldn't be sitting here, wearing nothing but a childish shirt and a bulky diaper, with the boy of her dreams right in front of her, complimenting her because she can say his name.  
  
Now, it  _really_  couldn't get worse.  
  
“Hm...what's that smell?”  
  
Or could it?  
  
Marinette's heart started racing again. She looked down. Her diaper wasn't wet. But as she turned her head around, she already saw Adrien, squatting behind her, pulling back the waistband of her diaper and making a disgusted face.  
  
“Phew! Smells like someone made a big stinky, huh?”  
  
No! No, it couldn't be!  
  
“Well, let's get you changed, hm?”  
  
No! This couldn't be happening!  
  
Adrien lifted her up, and she instinctively clung to him, crying. He rubbed her back gently, trying to comfort her.  
  
“There, there...it's alright Mari...Adrien will take care of you...”  
  
She hated that a part of her enjoyed this. She always fantasized about Adrien holding her in his arms, being gentle to her, caring for her. But this was not how she wanted this to happen.  
  
He put her down on the changing table in the corner of the room and went to fetch some changing supplies. It was bad enough having a wet diaper changed by a toddler in a public park. But despite this being a more private setting, having a full diaper changed by Adrien...it was the worst thing ever.  
  
“There,” Adrien said, bringing the supplies to the table, “now let's get this poopy Pampers off your baby butt, hm?”  
  
Marinette started full-out crying as Adrien undid the first tape on the diaper.  
  
“Shh...it's okay...”  
  
The sobs began with the second tape.  
  
“After all...”  
  
He slowly opened up the diaper and the stench of Marinette's own excrement hit her nose.  
  
“...you're just a baby!”  
  
Marinette started crying, and kicking, and screaming, closing her eyes in anger. Adrien seemed to ignore her and just started wiping her dirty bum as she bawled:  
  
“I'M NOT A BABY! I'M NOT A BABY! I'M NOT A BABY...”  
  
  
  
“...I'M NOT A BABY! I'M NOT A BABY! I'M NOT A BABY!”  
  
“Shh...shh...Marinette! Of course you're not! Marinette, wake up!”  
  
She opened her eyes, and saw Tikki floating above her. Without even saying anything, she grabbed the Kwami and started hugging her. After letting go, she threw up her blanket and gave a sigh of relief when she saw she was wearing her usual pajamas...and panties.  
  
“Muh...Marinette? Whu...”  
  
Tikki quickly hid under the blanket and Marinette turned to where the voice came from.  
  
“Manon! Good morning!”  
  
“Yes...guh...”  
  
The little girl let out a big yawn, making Marinette smile at how cute she looked. But then, she took on a more serious, almost sad expression.  
  
“Manon, I...I'm sorry for yelling at you last night. I just...nobody thinks you're a baby, you...”  
  
“Uh oh...”  
  
Marinette wasn't sure whether Manon had actually listened or not, but as she saw the little girl lift her blanket, she realized what was wrong. The pull-up she was wearing had clearly swelled up over night.  
  
“I...I...”  
  
Marinette went to hug Manon, who started sniffling.  
  
“M-maybe I am a b-baby...”  
  
“Shh...shh...no, you're not...you're a big girl, and let nobody tell you otherwise...”  
  
“B-but...”  
  
The girls looked up as the doorbell rang.  
  
“That must be your mom. Come, let's go to her. I won't even tell her about the tantrum you threw last night, but you have to promise me you'll start smiling again, okay?”  
  
Manon sniffled a bit, but managed to produce a smile.  
  
  
  
Manon and her mother were walking out of the Dupain-Cheng bakery and into the park, when suddenly, a figure all too familiar to both of them landed right in front of them.  
  
“LADYBUG!”  
  
Both Mrs Chamack as well as Ladybug smiled as Manon went to hug the red-clad hero.  
  
“Hello there, Manon! Say, can I talk to you for a second. Just the two of us?”  
  
Both Manon and Ladybug turned to Mrs Chamack, who at first looked surprised, but then smiled approvingly.  
  
Taking Manon aside, Ladybug told her:  
  
“My friend Marinette told me that you...have a little problem...”  
  
Manon looked surprised, then angry.  
  
“She said that...”  
  
“...it was a secret, yes. But she also told me you felt like a baby because of your problem. Is that right?”  
  
Manon just nodded, embarrassed. Ladybug leaned in and whispered:  
  
“Well, what if I told you that a certain bug you know had the same problem when she was your age?”  
  
Now, Manon's eyes lit up.  
  
“Really?”  
  
“Yes...I actually...was even a bit older than you. But...that's  _our_  secret, okay? Think you can keep it?”  
  
Manon nodded and hugged her hero.  
  
“Thank you.”  
  
“No problem, Manon.”


End file.
